Fuel burner liner



atomizing tip of a burner forv liquid fuel.

Patented July 21, 1953 U D sures FUEL BURNER LINER David Meyer, Canton, Ohio, assignor to Meyer- Balzer Fuel Unit, Incorporated, Dover, Ohio, a

corporation of Ohio 1 No Drawing. Application May 2, 1951,

Serial N0. 224,253

The invention relates to a liner construction for fuel burners, and .more particularly to a porous refractory liner composition for a combustion tunnel associated with the burner or Tlg e 1s application is a continuation in part of my prior co-pending application, Serial No. 686,950,1'iled July 29, 1946, and entitled Fuel Burner Liner.

and now abandoned.

'In burning liquid fuels, particularly fuel oil, if the atomized liquid fuel comes in contact with a metal surface, smoke and fumes'are produced because of the deposition or release of carbon at or adjacent to the metal surface; and thus only incomplete combustion is. obtained, and the burner efliciency is exceedingly low.

These difficulties have been sought to be overcome by providing a combustion. tunnelformed of refractory material into which air is dischargedand atomized fuel is also discharged from a liquid fuel'atomizing burner tip. Ordinarily the operation of such prior refractory combustion tunnels for fuel burners is in accordance with the well known principles of surface combustion. However, the refractory materials 11 Claims. (Cl. 15444) heretofore used are not of such nature as to I withstand the high temperatures developed within the combustion tunnel, for long periods of time without cracking, powdering, flaking, melting, or otherwise breaking down.

Moreover, although in refractory tunnels as compared with metal tunnels generally higher burner efficiency is obtained due to attainment of substantially complete combustion,.when the combustion-tunnel is heated .and when operated at high rates of fuel consumption; nevertheless, burners with prior refractory tunnels having high temperature resistance are difficult to start when cold, and are ineiiicient, and produce smoke and fumes at low fuel consumption rates.

To my knowledge, no prior refractory burner tunnel has had both the porous condition to promote substantially complete combustion and easy starting when cold, together with the ability to withstand high temperatures. without substantial deterioration.

Accordingly, it is a primary object of the present invention to provide a new porous refractory combustion tunnel material for a fuel burner,

such material having high heat resistance.

Another object is to provide a novel combustion tunnel which eliminates contact of the atomized liquid fuel or products of combustion thereof with any metal parts in the combustion tunnel of a fuel burner.v

Also, it is an object of the present invention to prevent the formation of fumes and smoke or the deposition of carbon, in the operation of a fuel oil burner.

Further, it is an object of the present invention to provide a refractory liner *material for-the combustion tunnel of a fueloil burner which is porous and absorbent such that a'portion at least of the atomized fuel is absorbed within the body of the refractory liner and thereafter re leased in a gaseous state in varying amounts depending upon the liner temperature.

Another object is to provide a porous absorbent refractory liner material for the combustion tun.- nel of a fuel burner which has exceedingly high heat resistance such that the material does not crack, powder, flake, melt or otherwise deteriorate during continued or extended operation of the burner, even at high temperatures existing in obtaining complete and efficient combustion.

Also, it is a general object of the present invention to improve the combustion, construction, manufacture, use and operation of the combustion tunnel of a fuel oil or liquid fuel burner so as to attain high burner and combustion eificiency, a longer burner tunnel life, and simplicity and ease of burner operation, not only in ignition, but in all stages of a wide range of burner fuel consumption rates.

Finally, it is an object of the present invention to provide a new tunnel liner composition for fuel burners which overcomes the prior art difficulties, which satisfactorily solves existing problems in the art, which incorporates the foregoing advantages in a simple and effective manner and which is inexpensive to manufacture and. safe and eiiicient in operation. These and other objects and advantages ap parent to those skilled in the art are obtained and the described difiiculties overcome by the compositions, combinations, and sub-combinations which comprise the present invention, the nature of which is set forth in the following general statement, preferred embodiments of which are set forth in the following description as exemplifying the best known modes of carrying out the invention, and which are particularly and distinctly pointed out and set forth in the ap pended claims forming part hereof.

The nature of the improvements in fuel burner liner composition may be stated in general terms as preferably including a liner formed of fire bri k o si icon-carbide m xed wi a suitable binder to wh ch mixture adde a. dry mixture opening or openings at one end into which air for combustion is drawn and through which the fuel oil atomizing tip of the burner discharges. The other end of the tunnel blockcommunicates with a furnace or other combustion chamber to be heated by the burner or into which the products of combustion are to be discharged.

The improved liner material is formed of a composition of firebrick or silicon-carbide, or the like, crushed or pulverized to about pea size, to which is added and mixed a ceramic binder such as dolomite, fiint clay or other clay or clays having high fusion properties and high heat resisting characteristics. The clays which may be used include Missouri clay, Bolivar clay, Sagger and Ball clay. Any one or a mixture of such clays may be used as the binder or grog for mixing with the firebrick or silicon-carbide.

One method of constructing a liner is to mix the crushed firebrick or the crushed silicon-carbide in the proportion of approximately 300 pounds firebrick or silicon-carbide to 1700 pounds of the binder, adding water and continuing mixing until the mass becomes rather stiff. If the combustion tunnel liner is to be used under extremely high burner temperatures, as for example, temperature approaching 3500" F. or 3500" F., silicon-carbide is used to give higher heat resistivity. However, if the burner temperatures are to be maintained below 3000 F., crushed firebrick is used instead of the silicon-carbide, because it is less expensive and gives practically the same results with respect to porosity and combustion efiiciency.

After the silicon-carbide or crushed firebrick and binder have been thoroughly mixed, the mass is sprinkled with a dry mixture of the following materials in the following proportions:

Parts Plaster of Paris 16 Powdered alum 1 Permanganate of potash 1 Salicylic acid 1 The quantity of the dry mixture used is approximately sixteen pounds to one ton of the plastic mass of binder and high fusion ceramic material already mixed. In other words, the ratio of the dry mixture to the plastic mass is about .8% by weight. After the dry mixture of chemicals has been thoroughly mixed with the high fusion ceramic mass, a quantity of the mixture may be rammed or pressed within a burner housing around a removable core in a relatively thin annular layer, to form a complete liner having a wall approximately three-fourths of an inch thick. The core is removed immediately and the liner is permitted to air dry or set, or may be heated to reduce the time of drying and setting.

While a combustion tunnel liner made in the foregoing manner is satisfactory for most installations, where the requirements of high p r s ty and hi h t mperature menial??? are particularly severe, slightly better results may be obtained by ramming alternate layers of the mixed mass of high fusion' material and the dry mixture of the chemicals into the burner housing around the removable core, substantially in the manner described in my co-pending application, Serial No. 686,950, of which the present application is a continuation in part.

When the mixed mass of high fusionceramic material and the dry mixture of chemicals are rammed in alternate layers in the burner housing, the firebrick or the silicon-carbide is first thoroughly mixed with the binder in the proportion of about 15% by weight of firebrick or silicon-carbide and 85% binder (which is the same proportion as 300 pounds to 1700 pounds),

vand. enough water added to make the mass of these .high fusion materials a somewhat stiff plastic mass. A quantity of this stiff mass is then introduced within the burner housing around a removable core in a layer of say l /z inches in thickness axially or longitudinally of the housing. This layer is rammed or pressed in place and then a small quantity of the dry mixture of chemicals, in the proportions previously set forth, is sprinkled over the pressed plastic mass in a very thin layer of the order of paper thinness, and this dry layer is rammed or pressed onto the moist layer of the high fusion mass. Alternate layers of the plastic high fusion mass and the dry mixture are added and rammed into the burner housing around the core until the complete liner has been formed, the layers of the moist high fusion plastic mass being substantially 1% inches thick when introduced and the sprinkled layers of dry chemical mixture being of substantially paper-like thickness.

After the complete liner has been formed, the core is removed immediately and the rammed liner is dried either in the air or by the addition of heat. The completed liner has a substantially laminated construction, although due to the ramming operation, the separations between the layers are somewhat imperfect and uneven and the thickness of the layers of the high fusion ceramic mass axially of the housing is of the order of about three-fourths of an inch. Obviously, the thickness of the layers of the moist high fusion mass may vary considerably due to variations in the moisture content and to the amount of pressure used during the ramming operation. However, when the novel combustion tunnel liner is made by ramming alternate layers of the moist high fusion mass with the dry chemical mixture, the finished tube is substantially laminated, having alternate layers of the high fusion ceramic material with alternating very thin paper-like layers of the chemical mixture. In the finished liner, the proportion of the chemical mixture is roughly .8% by weight of the high fusion mass (firebrick or silicon-carbide and binder) which is the same as sixteen pounds to the ton.

It is to be understood, that the proportions given for the high fusion plastic mass consisting of the binder material and the firebrick or siliconcarbide, and for the dry mixture of chemicals, are preferred proportions to attain the best results, but these proportions may be varied somewhat to produce liners having different degrees of porosity and heat resistance in accordance with the requirements of different installations. The preferred proportions heretofore set forth have been found to produce themost desirable degrees of porosity and the-highest heat resistance the finished liner for .a large majority ,of

installations.

A liner. of the foregoing composition and produced in either of the described manners is a {porous and absorbent structure with [extremely high heat resistance. "The liner instantaneously absorbs a portion of atomized liquid fuel or fuel oil discharged therein from the atomizing tip of 'the fuel burner, and produces substantially in- -stan'taneous and complete combustion with a characteristic incandescent flame. "These :unusual results may be produced by the complete .de-

composition and gasification of the fuel particles which have been absorbed into the porous liner material.

Burners equipped with the novel liner'combustion may be lighted substantially instantaneous- "1y when cold without preheating, apparently because of the charge of fuel particles with-in the porous structure of the liner after previous use has been discontinued. .When air is introduced through the cold liner, apparently the gas from tory material is not known. It may be that the action of the improved combustion tunnel liner composition is in part catalytic. However, it has been found in actual practice that the combustion tunnel material enables a completely combustible gaseous mixture to form within the tunnel before any atomized liquid meets or reaches the zone of ignition of flame-propagation. The

gaseous fuel given off from within the porous liner and at the surface thereof probably mixes with air to provide for complete combustion, and this is evidenced in operation of burners equipped with the improved liner composition by the complete absence of fumes, smoke or carbon monoxide. Accordingly, high burner efficiency is attained and maximum heat is developed in the chamber into which the burner discharges. For the same reasons if the burner is used to supply an explosive mixture of gas and air to an internal combustion engine, a maximum amount of power will be developed by the engine.

The improved liner composition may be used in connection with gas welding by atomizing the liquid fuel into a heated porous absorbent refractory tube of the improved composition, through which air may be forced to mass with the gaseous fuel given off from the porous liner, and the mixture of gas and air continued to a welding torch where additional air or other gases may be mixed therewith to provide a suitable Welding flame.

Although the burner construction has been described as including a liner of the novel composition formed within a metal burner housing, it is to be understood that a metal housing may be eliminated if the combustion tunnel is formed of the improved composition with sufiicient wall thickness to provide the required degree of strength to maintain its shape, and if the outer surface thereof is sealed in some manner, as by glazing or the like, to prevent absorption of moisture, or gases or other material through its outer surface.

Having now described the features of the invention, the composition of a preferred form of improved fuel burner combustion tunnelliner, and the new and useful results attainedthereby; the new and useful liner compositions are set forth in the appended claims.

I claim:

1. A :porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed firebrick and high fusion ceramic binder material selected from the class of high fusion clays and dolomite, said body containing a small quantity of a mixture of about one part by weight each of powdered alum, permanganate of potash and salicylic acid, and sixteen parts of plaster of Paris,v the ratio of the mixture to the body material being approximately sixteen pounds to the ton. V

2. A porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed silicon-carbide and high fusion ceramic binder material selected from the class of high fusion clays and dolomite, said body containing a small quantity of a mixture of about one part by weight each of powdered alum, permanganate of potash and salicylic acid, and sixteen parts of plaster of Paris, the ratio of the mixture to the body material being approximately sixteen pounds to the ton.

3. A'porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed porous high fusion ceramic material and high fusion ceramic binder material selected from the class of high fusion clays and dolomite, said body containing a small quantity of a mixture of about one part by weight each of powdered alum, permanganate of potash and salicylic acid, and sixteen parts of plaster of Paris, the ratio of the mixture to the body material being approximately sixteen pounds to the ton.

4. A porous refractory fuel burner liner material comprising a body of crushed high fusion ceramic'material selected from the class consisting of firebrick and silicon-carbide mixed with binder material selected from the class of high fusion clays and dolomite, said body containing a small quantity of a mixture of about one part by weight each of powdered alum, permanganate of potash and salicylic acid, and sixteen parts of plaster of Paris, the ratio of the mixture to the body material being approximately sixteen pounds to the ton.

5. A porous refractory fuel burner liner composition material comprising a body of crushed high'fusion ceramic material selected from the class consisting of firebrick and silicon-carbide mixed with binder material selected from the class of high fusion clays and dolomite, the proportion of high fusion ceramic material to binder material being approximately 300 pounds to 1700 pounds, said body containing a small quantity of a mixture of about one part by Weight each of powdered alum, permanganate of potash and salicyclic acid, and sixteen parts of plaster of Paris, the ratio of the mixture to the body material being approximately sixteen pounds to the ton.

. 6. A porous refractory fuel burner combustion tunnel liner material consisting of relatively thick layers of a body of crushed high fusion ceramic material selected from the class consisting of firebrick and silicon-carbide mixed with binder material selected from the class of high fusion clays and dolomite, and paper thin layers of a mixture of about one part by weight each of powdered alum, permanganate of pot-' ash and salicyclic acid, and sixteen parts of plaster of'Paris, the amount of the mixture being approximately .8% by weight of the body material.

7. A porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed high fusion ceramic material selected from the class consisting of firebrick and siliconcarbide mixed with binder material selected from the class of high fusion clays and dolomite, said liner material containing compressed layers of the body material approximately three-fourths of an inch thick alternating with paper thin layers of a mixture of about one part by Weight each of powdered alum, permanganate of potash and salicyclic acid, and sixteen parts of plaster of Paris, the amount of the mixture being approximately .8% by weight of the body material.

8. A porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed high fusion ceramic material selected from the class consisting of firebrick and siliconcarbide mixed with binder material selected from the class of high fusion clays and dolomite, the proportion of said high fusion ceramic material being approximately 15% by weight of the binder material, and said liner material containing paper thin layers of a mixture of about one part by weight each of powdered alum, permanganate of potash and salicyclic acid, and sixteen parts of plaster of Paris, the amount of the mixture being approximately 11% by weight of the body material.

9. A porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed high fusion ceramic material selected from the class consisting of firebrick and siliconcarbide mixed with binder material selected from the class of high fusion clays and dolomite, the proportion of said high fusion ceramic material being approximately 15% by weight of the binder material, and said liner material containing compressed layers of the body material approximately three-fourths of an inchthick alternating with paper thin layers of a mixture of about one part by weight each' of powdered alum, permanganate of potash and salicyclic acid, and sixteen parts of plaster of Paris, the amount of the mixture being approximately .8% by weight of the body material.

10. A porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed firebrick and binder clay in the proportions of approximately 15% firebrick and 85% binder clay by weight, said liner material containing compressed layers of body material approximately three-fourths of an inch thick alternating with paper thin layers of a mixture of about one part by weight each of powdered alum, permanganate of potash and salicyclic acid, and sixteen parts of plaster of Paris, the amount of the mixture being approximately .8% by Weight of the body material.

11. A porous refractory fuel burner combustion tunnel liner material consisting of a body of crushed silicon-carbide and binder clay in the proportions of approximately 15% silicon-carbide and 85% binder clay by weight, said liner material containing compressed layers of body material approximately three-fourths of an inch thick alternating with paper thin layers of a mixture of about one part by weight each of powdered alum, permanganate of potash and salicyclic acid and sixteen parts of plaster of Paris, the amount of the mixture being approximately .8% by weight of the body material.

DAVID MEYER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,345,377 Linbarger July 6, 1920 2,014,065 Dean Sept. 10, 1935 2,364,108 Swentzel Dec. 5, 1944 

6. A POROUS REFRACTORY FUEL BURNER COMBUSTIONSTION TUNNEL LINER MATERIAL CONSISTING OF RELATIVELY THICK LAYERS OF A BODY OF CRUSHED HIGH FUSION CERAMIC MATERIAL SELECTED FROM THE CLASS CONSISTING OF FIREBRICK AND SILICON-CARBIDE MIXED WITH BINDER MATERIAL SELECTED FROM THE CLASS OF HIGH FUSION CLAYS AND DOLOMITE, AND PAPER THIN LAYERS OF A MIXTURE OF ABOUT ONE PART BY WEIGHT EACH OF POWDERED ALUM, PERMANGANATE OF POTASH AND SALICYCLIC ACID, AND SIXTEEN PARTS OF PLASTER OF PARIS, THE AMOUNT OF THE MIXTURE BEING APPROXIMATELY .8% BY WEIGHT OF THE BODY MATERIAL. 